Ultraviolet sterilizer



Aug. 7, 1945.. R. A,l HRABAK 2,381,452

ULTRAVIOLET STER-:LI ZER INVENTOR. Raaf/zr A'. HRABAK ATTORNEYS yearths atmosphere.

f earths atmosphere.

f, alternating electric circuits,

-r' Patented Aug. 7,l 12945 y j Robert A. Hrabak, Lakewood, ohio, assigor to The Art Metal Company, Cleveland, Ohio, a corf poration of Ohioy s Application January 2, 1943, Serial No. 471,194

(C1. 25o-ss) n r 14 Claims. rThis invention relates to ultraviolet sterilizers,

' and while devices embodying the present invention are suitable forvarious sterilizing purposes, such devicesv are particularly useful in effecting air sterilization or sanitary ventilation.

It is now an accepted fact that ultraviolet radiations, particularly in the spectral range 2000 to 3000 Angstromunits, are quite effective in killing bacteria of disease-carrying species. Although ultraviolet radiations within the aforesaidr germicidal range form a fractionalpart ofthe invisible spectrum originating in the sun, such radiations are largely absorbedin the upper layers of the germicidaifrequency are injurious Ato the human system, especially to the skin and eyes,y it is perhaps fortunate that the suns germicidal ultraviolet radiations are largely absorbed `by the However, lamps for1 artificially generating ultraviolet radiations of germicida] frequency are now available, lamps which y are of conveniently sized tube form, of low. operating cost and which are operative from ordinary A substantialv proportion of the output of such lamps is ultraviolet I energy at a resonance radiation of 2537 A., which is not far removed from the preferred germicidal radiation of approximately 2650 A.

The present invention has for one of its objects the provision of an ultraviolet sterilizer in which is used a lamp of Athe aforesaid character, said sterilivzerhaving simple and inexpensive means for supporting the ultraviolet lamp, for enclosing the ballast necessary for the operation of the lamp, and for eciently directing to the desired regions, for effective sterilizing purposes, theultraviolet radiations emitted by said lamp.

A further object of the present invention is the provision vof an ultraviolet sterilizer; adapted for suspension in asubstantially horizontal position rfrom anl overhead supportsu`ch as from a ceiling of a roomor chamber, and in which the ultra-y violet radiations emanating from the sterilizer lampv pass upwardly and outwardly from both f sides of said lamp, to thereby eifectivelyfirradiate by. germicidal ultraviolet the y s y upper regions of such a roomor chamber.`

f v A further object-ofthe present invention is the A further object of the present invention isthe- Inasmuchfas. extended or4 "prolongedexposure to ultraviolet radiations of provision of a ceiling type ultraviolet sterilizerA which not only diverts upwardly and laterally, from each side of the sterilizer, germicidal ultraviolet emanating from the sterilizer lamp but which also diverts downwardly, in theV form of a curtain or screen, germicidal ultraviolet emanat,

ing from said lamp. With such a sterilizer, it not only is possible to effectively irradiate by germicidal ultraviolet the upper Lregions of as room or chamber but also, to provide a' downwardly directed curtain or screen of germicidal ultraviolet, which enables the sections of the room'or cham. ber lying on opposite'sides of said curtain or screen to be effectively isolated from each other.

A further object of the present invention'isthe provision of an ultraviolet sterilizer having a separate closure for the opening through which pass the downwardly directed ultraviolet. radiations,

thereby enabling ifdesired, all ultraviolet radiations emanating from the' sterilizer lamp to` beV used for the irradiation of the upper regions of the room or' chamber in which the sterilizersis suspended. l v f A further object of the presentinvention is the provision of an ultraviolet sterilizer in which the lamp thereof is mounted ybelow and in substantial alignment with a housing of the sterilizer which encloses the ballast-for saidlamp, said housing being provided along its bottom surface withreflector means for cooperation with other reflector means in directing upwardly and laterally from both sides of the sterilizer, germicidal ultraviolet emanating from said lamp.

A further object of the present invention is the provision of an `ultraviolet sterilizer having structural and manufacturing simplicity, parts which can Ibe readily and conveniently assembled, and which possess high operating eiciency.

'Ihe present invention will be readily understood and many of its practical advantages will be evident from the following descriptionof one,

embodiment ofthe invention, as illustrated in the accompanying drawings, in which Fig. 1- is a top plan view of an ultraviolet sterilizer embodying the present invention, the opening of s aid Vsterilizer, for the downward passage of a curtain or screen of germicidal ultraviolet, being uncovered;

Fig.` 2 is an elevational view representative of each of the two sides of said sterilizer;

Fig. 3 isa left end elevational view thereof; Fig. 4 is a right end elevational view thereof;

Fig. 5 is a bottom planview thereof;

Fig. 6 is a cross-sectional view of the sterilizer, on the line 6 6 of Fig. 1;

per housing part of Fig. 8, with the cover of said housing part off and disposed at one 'side toshow the interior of said housing part;

Fig. 10 is a diagrammatic illustration of a room or chamber in which is suspended, from the ceiling thereof, the aforesaid sterilizer, the downward directed curtain or screen of germicidal ultraviolet being confined betweentWo-bedsin saidroom or chamber; and

Fig. 11 is a view, partly in end elevation and partly in vertical section, showing Ala. closure for the sterilizer opening through which germicidal ultraviolet passes downwardly in the form of a curtainor screen, the closing of said opening causing all ultraviolet 'radiationsemanating from the rsterilizer. lamp to pass upwardly and' laterally from both sides of the sterilizer.y

Before the ultraviolet sterilizer here illustrated is specifically described,- itis `to be understood ythat the invention here involved isnot limited to the details of construction or the exact arrangement of parts hereinillustrated or described, as the invention obviously may take other` forms. It also is to be understood that the phraseology or terminology herein employed is for the purpose of description and not of limitation, the scope of the present invention being denoted bythe appended t claims.

M As will be evident from the accompanying drawings, particularly from Fig. `8, the ultraviolet sterilizer here illustrated, for the disclosure of one form of the present invention, comprises two main parts, there beinganupper partfor suspension in a substantially horizontal, position froman overhead support, and a.lowerv part connected to and suspended from saidupper part.

As bestshown in Fig. 8said upper part comprises an elongated housing I of sheet metal or like material and of generally rectangular shape in vertical section. Suitably mounted in said housing, at the ends thereof, are two depending lamp holders I I, andisuitabl'y secured to the end portions of the housing top wall I3 are two rings I4 or equivalent means for use in the suspension of the'sterilizer from`y an overhead support, such.

as from a ceilingof a room or chamber. Suitably secured' to the housing'land underlying its bottom `wall is a reflector I5to be hereinafter referred to.

The lower part ofthe sterilizer, as clearly shown in Fig. 8, comprisesa pair of endwalls for securement vto the end walls I'I of the housing |0, and a pair'of laterally spaced elongated reflectors I8-which cooperate with the upper reflector I5 ink directing upwardly and laterally from both sides of the sterilizer, in la manner which will hereinafter more fully appear, the-ultraviolet radiations emitted by the sterili'zer lamp. The slot; 20 pro-l vided by the lateral `spacing of thereflectors I8 permits some of the ultraviolet radiations emanating from the sterilizers lamp to pass downwardly in the form of a curtain or screen, and to confiner any suitable manner.

able fabricating methods may be employed. As here shown, the top'wall I3 and the side walls 2| of the housingID are integral parts of a simple and inexpensive sheet metal stamping, the side walls being bent at right angles to the top wall. The end walls I'I are separate sheet metal members welded or otherwisesuitably secured in place, the present end walls having side edge tabs 22 (see Figs. 7 and 9) for securement to the side Walls 2| and top edge tabs 22a for securement to the top wall |3. The housing I0 as thus formed is open at. its bottom and to normally close said bottom opening, a separate sheet metal member 2327 is" here utilized. This closure member constitutes, of course', the housing bottom wall and its secur'ement-I inclosing position may be effected in As here shown, the housing side walls 2| are internally bridged, at the end portions thereof, by a pair of cross straps 24 to which the housingY closure member or bottom wall 2'3is removably secured,'the cross straps 24 being here provided with depending end portions 25 which. are welded` or otherwiseV rigidly secured to the inner surfaces of thev housing side walls 2|. As will beevident from Fig. 7, screws 2'Ijare'here' utilized to secure the housing closure member or bottom wall 23`to the cross straps 24, the intermediate portions of said straps being provided with threaded apertures 28 (Fig. 9) to hold saidscrews and the4 housing closure member orb'ottom'vvallbeing provided with longitudinallydisposed slots 29' orthe like to receive said screws: lIf desired and as here shown, the housing closure member, or bottom wall 23 may be provided with upstanding side flanges 30 for telescopic relationship with the housing side walls 23, said' walls preferably lying between said flanges, as shown.

As best shown in Figs. 7 and 9, the lamp holders I'I extend through suitable apertures in the end portions of the bottom closure member 23 of the housing I0, said lamp holders having enlarged upper 'end portions `I Ia which lie within said housing and whichare suitably secured, such as by the'screws 32; to the housing closure member 23; Secured to and' electrically connected with theenclosed upper end portion Ila' of one of the lamp holders I I (,the left end one thereof, as viewed in the drawings) is a socketed support 33 forthestarter 34 which is necessary for the operation of'an ultraviolet lamp of the character here used'. As best* shown in Figs'. 2 and '7, said starter projects downwardly from its support 33.and extends'through a suitable aperture 35 in the housingclosure member or bottom wall 23. As a resuit, thelower end of the starter is always exposed for convenient manipulation in attaching the starter to and detaching it from the support 33 therefor.

A ballast 3l also is necessaryvfor the operation of the sterilizer lamp, and such ballast is mounted within and thus enclosed by the housing Ill. As bestshown in Figs. 6 and 9, the ballast 37| lies alongside `the inner surface of one of the housing side wallsZI, the apertured end lugs 38 with' which such ballast-,is provided being screwed or otherwise rigidly secured to such wall. Also locatedwithin and enclosed by-the housing I0 is the'wiring 39 (see Fig. 9) by which the lamp holders I', the starter34- and the ballast 3'I are electrically connected, and extending outwardly from said'housing, through anaperture 40 in its right end wall II as here shown, isrthe wiring 42 for use v in the connection of the sterilizer to a source of '15 v alternating current.

2,381,452 -3 *Asbest shewniinrigitgthe renectorlsjis a simple sheet metal member offV-shaped cross section, f Vsaid member beingsymmetrically disposed ben'aath' thehousing' Iand havingupstanding side vfilaiileges'55 whichjlie alongside the inner surfaces thereof, as shown, in Figs.6 and 7.

1 f For' theconnectionof the end walls of the lower i 'part ofthe sterilizer to the housing end walls I'I of vedge jf'anges 1 3I whichfembrace `and which are fthe'upper'partthereof, screws 5'I are here utilized,

` yweldefd orotherwise rigidly secured to the correspending anges E3 0 of `the ,housing'bottom closure "niember "23. 'The 'length of the reflector I5 yis here suchfft'hatoitfextendsufrom the right end lamp holder H ,'fasljviewed in; the drawings, t'o the de- :1Q pending starter. 3 4, vand toaifford accessto Ithe' screws f2] by whichthehousing bottomf closurel 23 isrernovablysecured tothe housing cross straps '-'walls a' likeaperture may be providedin the other -Fend walliof the housing as here shown( l, A's'z'vbest'shown4 in Fig. 6", thel upper andlower perfalnd lower fpartsof the sterilizer are'substanf tiallycoeitensive in lengths. As heretofore pointed om. the'lowei' partof the sterilizer comprises a 'pairf'end'walla foiconnection to the end walls? -20^ v I I of/the housing Iilgfa' 'pairr o f V laterally spaced elonfgatedreectors `I ,i`or coopera-tion With the rupperreflector I5fin directing upwardly and laterally ,f from. both 'sides of the ysterilizer the Amaj or y portion ofthe ultraviolet radiations emitted by there sterilizers lamp, and 'a yseries of laterally connectfed depending walls at the peripheryof th'e slot ZD between thel spaced reflectors i I8to provide a 'due'tfcr passageway fory the ultraviolet radiations which pass k downwardly 'through said slot in the"3 form o f a curtain 0r screen.

sterilizer.;` any suitablek fabricating methods kmay be employed. A s here sh'own, the laterally spaced reflectors ldare provided alongtheir inner sida-35 edges gwith integraldepending flanges 4 6 which consti-tute the duct side walls, and are vprovided at their; end edges with; upstanding integral flanges Q41 of generally triangular shape which constitute thecuterportions o f ,the end Iwalls ofthe lower"'40' sterilizer part. 'Ifhemiddle portions lof, said end :wallsare theupper end :portions dwcf .separate sheet metal members, the depending lowerend portions;49 of .which constitute the duct end walls. v ;lsfulieres lioyvri", 'the sideedgesof vthe midc'ilefend 45" lwall, po1'tions'-ll-i3abut the'adjacent edges o f the '.Qtrgend weuip'rmnsAL 'andtoleifect @simple -yet c lurablle rn intenanceof theseportions'in as'- f As`e r 1f1l01i, 'Separate sheet metal members 5U lare here Welded or otherwise secured to the innerv surfaces 1'50 @fthe-middle end Ewan portions mythe jwidth. of

frnembe'rs 5 0beng such` that 'said members overlap theadjacent edge'parts ofthe outer end wall p oraraof gradually increasin'gwidth'from top to b'ot tom, as bestlsliown inFigs.-3 and'fl. For the lateralk connection Eo'fethe duct walls, `the "duct end walls V49' are-hereprovided with'iriwardly' f'extending "65' flanges 5 I` 'which'- receive therebetween and lwhich,

Y arezwelded or otherwise rigidlysecured to theend edgesof the'dubtside walls T46; i l

" i4Forincreasedstrength'and rigidity; therefleytcrs' I8: farefherexprovided' at ftheir outerside '70 edges? with* dependingfiU -sh'aped 'flanges L53) and similar dlanges `54l project laterally l from thfek bottom edgesy of the' ductside walls 4.6. For this Vsame prposefthe duct vend walls'ISmay'be and' h'e're "fthe co'nnectionof thesel parts being such that the lower 'sterilizer' partis suspended the desired dis- 'f tancebelowfthefuppersterilizer part (see Fig. 7). Preferably,'the housing-end Walls I'I are provided with tapping plates 5 8 to 'more securely hold the screws-Hime present tapping plates being welded I; or otherwise suitably secured Ato th'e inner surfaces f 'of said/end walls'. VVV-`mounted `in"the-housing end wall aperture 40 If-fdesired, an yeyelet may be through whichextends the outlet wiring 4-2', and to parts'offthe steriliz'er are so connected that the laterally spaced lower reilectors I8`are symmetri- 1 cally "disposed with respect to the upper V-shaped wrflec,to1"l5.` flt'also'will be noted from Fig. 6 fthatwhen the sterilizer is horizontally disposed- "its'disp'osition when `in use, thelower reectors JIareupwardly and laterally inclined from the f'fslo't '20therebetween,'the 'angularity of such renectors being somewhatless, as here shown, than x-thatof theftwo sides of the upper V-shaped reector iI'5. From Fig. 6, it'also will'be evident f :that `the ultraviolet lamp'GZ, which is detachably lcarried by t'hedepending lamp holders rI I; is positioned'directly'below the linefof convergence 4ofthe two'sidesA ofthe upper reflector' I5 and directlylabove the longitudinal axis of the duct beloW-"the'slot 20 between the two lower reflectors I 8. yInasmuch astheflamp forms no part, per

se, of the present invention, yit is sufficient to here statethatisa'id'lamp is` of thehot' cathode', low voltage? vktubeltypeg' the mercury 'arc discharge of -whichfisthe source of 'the ultraviolet radiations. 'A`su`bstantial proportion of such radiations are at a resonanceradiation of 2537 A.,'whi ch is not far removed-from thepreferred germicidal radiationof lapproxir'nately 2650 A. The cylindrical walllofV 'said lamp f'is of glass' having special wave transmitting characteristics, and the metal'end :caps 63 `ofthe lanp are provided withthe usual 1 paired andlongitudinally disposed contact prongs 4(notsliown in the-'present drawings) for both mechanical and electrical connection of the lamp to the depending lamp holders II.

AFor purposes of illustration, there is diagram- Amatically illustrated in Fig. 10 a room or chamber 64 in which is `horizontally suspended from the ceiling '65`thereof,' by vmeans of drop 'chains or equivalent means IIiconnected'to the sterilizer leye membersIlI, an ultraviolet sterilizer of the character heretofore described. As kwill be evident from this view, a major portion ofthe ultraviolet radiations emitted by the lamp 62 fare" directed upwardly'and-laterally by the cooperating reectors I5, I8 from' both sides of the sterilizer. Tests Arecently made indicate that the most eilicient method of using bactericidal ultraviolet for air sterilization or'sanitary ventilation of a room or vchamber is Aby the direct irradiation of the airiin' `the upper regions of said room or chamber, and as the present sterilizer directs this ultaviolet`from"b`oth`of its sides to lthe upper regions of the room or chamber in which it is mounted, isparticularlyeil'ective in achieving airsterilization or sanitary ventilation of said room or chamber. rvObvou'sly if the room or chamber is especially long, one or more additional lsterilizers v by the dotted line circle 69.

may be mounted therealong, in a mannerwhich will be readily understood.`

The operating characteristics of an ultraviolet lamp of the character here used are such that the ultraviolet radiations `emitted by said lamp originate in a generally cylindrical .zone 68 `extending between-the terminal electrodes of the lamp and indicated in sectional outline in Fig. 6 As will be evident from Fig. 6,` `the longitudinal axis of this generating zone 68 is coincident with the longitudinal axis of the lamp, the diameter of said zone being substantially one-half of the lamp diameter. Therefore, in order to prevent any of the ultraviolet radiations directed laterally by the reflectors I5,` I8 from diverging below the horizontal, when the sterilizer is horizontally suspended, the lower reectors I8 extend upwardly to the horizontal plane tangential to the top of the lamp generating-zone 68, as will beevident from both Figs. 6 and 10.

It is at times desirable not only to irradiate by germicidal ultraviolet the upper regions of a room or, chamber but'also, to provide in such room or chamber a downward` curtain or screen of germicidal ultraviolet. Such a curtain or screen of germicidal ultraviolet is here effected by the provision `of the slot 20, between the laterally spaced lower reflectors I8, and by the downwardly directed duct communicating with such slot. f The disposition ofthe duct walls and extent of their dependency determine, of course, the area. covered by the downward curvtain or screen of germicidal ultraviolet, and in expected, of course, that -noone will remain'for any extended period of time in the lpath of said ultraviolet curtain vor screenas prolonged exposure Lthereto .is.q-inadvisable. However, no harmful effects .are experiencedV by one who briefly passes in or walks Athrough or valong -theultraviolet curtain or screen. f u l Ifl it is desired Ito vconiineto the upper regions of the room `or chamber 64 ltheultraviolet radiations emitted byf the lamp of the sterilizer mounted inK said room or` chamber, it is merelyl necessary to cover ythe slot20 between the laterally spaced lower reflectors I8 of such sterilizer. In Fig. 11 is illustrated the sterilizer of Figs. l to inclusive with a sheet metal cover member I0 for the sterilizer slot 2l).` Ashere shown, this cover member 'I0 is of sufficient width to enable its longitudinal or side edge portions to rest upon the adjacent inner edge portions of the reflectors I8 with the consequent support of said member in slot-covering position, the length of said cover member being at least as great asthat of the slot 2l). Preferably and asihere shown, the longitudinal or side edgeportions of the cover member 'I0 are upwardly inclined to conform to the upward inclinationof the reflector portions upon which they rest, so thatthe covermember is more` or less laterally self-.adjusting toits covering position. If desired, said cover member may be provided with oneV or more, depending cross strips which extend. into and thereby cooperate with the slot 20 in positioning thecover member over saidslot. As here shown there are two such cross strips 12, one located adjacent each end of the cover member, said cross strips comprising the .depending inner end portions of sheet metal angle members having their outer end portions in contact with, and welded or otherwise suitably secured to, the lower surface of the end portions of the cover member. rBy making the upper surface of the cover member 'IU-,0f reflecting character, so that it' constitutes, in effect, a

of the lower sterilizer part and the inner surfaces of the duct walls, particularly the side walls 46, may be similarly plated.

From the foregoing description thereof, it will be evident that the ultraviolet sterilizer here illustrated and described is of simple and inexpensive construction, of relatively compact form, of neat and pleasing design and of high operating efficiency. The ballast and internal wiring of the 'sterilizer are completelyenclosed and thereby concealed from view, and the reflectors of the sterilizer are so arranged as to efficiently direct to both sides of fthe sterilizer, in upward and outward directions, the ultraviolet `radiations impinging thereon. In addition to effectively irradiating by germicidal ultraviolet the upper regions of the room or chamber Iin which it is mounted, the present sterilizer provides, if desired, a downward curtain i or screen of germicidal ultraviolet, Awhich is of material benet in isolating from one another sections of said room or chamber. If said downward ultraviolet curtain or screen is not desired, its elimination can be easily and quickly effected by the use of the cover member 10, and as said cover member is merely 'laid in coveringl position, its application and removal can be almost instantly effected. Asv the germicidal ultraviolet is directed upwardly and laterally from both sides of the sterilizer. a

widespread distribution of the ultraviolet results,

vof ultraviolet sterilizers embodying suchv invention will be evident from the foregoing description of one such embodiment.

f `Having described my invention, I claim:

1. An-ultraviolet sterilizer, comprising an elongated support having a pair of longitudinally spaced lamp holders depending therefrom, a tube type ultraviolet lamp extending between and carried by said lamp holders beneath said-support, aballast for said lamp carried by said support,

lelongated reflector means suspended from said support for directing laterally fromvboth sides of the sterilizer ultraviolet radiations emitted by said lamp, said refiector means having an opening'beneath `said lamp to permit some of the ultraviolet radiations emitted by'said lamp to ,()fpenl'lilg.V I ,t

A2.- An ulti" violet sterilizer, comprising arr-elongated supporty 'shaving a lpair of longitudinally .-fpassf downwardly therethrough; andfdepending continuous wall means vat the periphery of said y'opening to provide aldownwardly/v directed duct for v.ultraviolet radiations.. passing. through l lsaid spaced lamp holders depending therefrom, Ia

' .tube type'ultraviolety lamp'extending between fandlcarriedA by said v'lamp' holders beneathsaid support, ya ballastrfor said lamp'carried by said support, f elongate-d' freflectoru 'means suspended v-fronfr saidsupport for. directing "laterallydrom both sidesfcf'the-'sterilizer rultraviolet radiations emitted "by s'aidflamp, saidv reflector' means' having anelongated :opening beneath and in'alignthrough. said opening; the; side walls* of l said duct being ofdownwardlyf'divergingform; f

.3.1 An' ultraviolet sterilizer/cornprising' an elongated fsupport" havingl a fpair' off longitudinally spaced lamp holders dependingtherefrom, 'a ltube type? ultraviolet"lamp extending between and "carfried by said 4lamp' kholders beneath said support,

upwardly facingf'elongated reflector :portions sus# pended yfrom said supportforf directing laterally Yfrom both :sides of `tl'ley steilizer ultraviolet radia- .tions emitted' by said.;lamp, said v'-reflecstorportionsv being separatedby'ari-'opening located below saiddamplan'd permitting some of the ultra- -violet radiations emitted by said lamp to pass downwardly therethrough, and a removable coverv `member for closing said opening.

. 4. An ultraviolet sterilizer, `comprising an elongated-supportv having a jpair offlongitudinally spaced lamp holders depending therefrom, a tube type ultraviolet lamp extending between and carried by said" lamp holders' beneath said support,

upwardly facing elongated reflector means susp'ended from said support fordirecting laterally v from both sides 0f the sterilizer ultraviolet radiations emitted by said lamp, a portion of said reflector means` being removable to provide an elongated opening below said lamp which permits some of the ultraviolet radiations emitted by said lamp to pass downwardlytherethrough.

5. An ultraviolet steriIiZer, comprising an elon`v gated support havinga pair I of longitudinally.

spaced lamp holders depending therefrom, a tube type ultraviolet lamp extending between and carried by said lamp holders beneath said support, upwardly facing elongated reflector means sus pended from said support `for directing laterally from kboth sides of the sterilizer ultraviolet radiations emitted by said lamp, said reflectormeans having a generally at reflector portion'ilocated below saidv lamp and also having upwardly and vlaterally inclined reflector portions on opposite sides of said generally flat portion, said generally flat portion being removable to provide below said lamp an openingthrough which downwardly may pass some4 of the ultraviolet radiations emitted by said lamp.

6. lAn ultraviolet sterilizer,comprising an elongated support having a pair of rlongitudinally spaced lamp holders depending therefrom, a tube type ultraviolet lamp extending between andcarl ried by said lamp holders beneath said support,

upwardly facing `elongated reflector means vsuspended from said support for directing laterally 'from both-'sides orthe'sterilizer ultravloletradiations emitted by said lamp, said reflectorl means having i an -elongatedziopening f located beneath f 'and in alignment' with said' lamp 'andl also having f 5 `4upwardly I and laterally.inclinedreector portions on opposite "sides of said opening;` said f opening 'permitting lsome ofv the 'ultraviolet' radiations emitted by said lamp'tovpa'ss :downwardly there- ".7, An ultraviolet sterilizer, comprising. an'elongated support having aA pair' i vof' longitudinally spacedvlamp holders depending therefrom, a tube type ultraviolet 'lamp extending between and vcar- Jried by -said lamp holders" beneath and spaced '.,froinsaid support, downwardly facing elongated )upper reector'means carried by said support in lthe spacebetween it and said lamp, and upwardly facing elongated lower reilectorfmeans suspended 201i from' said'support and cooperable with said upper reflector means in directing laterally fromboth sides of fthe sterilizer ultraviolet' radiations "ernittedlby said lamp,` said 'lower reilec'torr'neans 'extending laterallyjbeyond that of 'said upper re-y 'hector' means-and having anopeningbejlow said upper-v r'enector means, )said vopening' Apermitting 'some' ofthe ultraviolet'radiations emitted by said llamp to pass-downwardly therethrough'. "f"

1 8. yAn''ultraviolet steriliz'en'fcoinprisin'g an elonspaced lamp' holders depending therefrom, a tube type ultraviolet lamp' extending'between and carf'ried by saidv lamp vholders` beneath said' support -and substantially 'in angnment with the lengt.

' tudinal axisof said supporu'said lamp' havingan ultraviolet generating zone having its longitudinal axis substantially coincident with the longitudinal'axis of the lamp, andupwardly facing elongated; reflector means Asuspended from said 40 support for directing laterally from both sides of the sterilizer ultraviolet radiations emitted' by said lamp, the outer side edges ofsaid reflector means being disposed at all timessubstantially in a horizontal plane f tangential to the top of the lamp generating zone, whereby ultraviolet radiations directed laterally from the sterilizer are prevented from diverging below the horizontal.

9. An Vultraviolet sterilizer, comprising an elonk gated' supportl having a pair of longitudinally spaced lamp holders depending therefrom, a' tube type ultraviolet lamp extending between and carried by said lamp holders beneath and spaced said support and cooperable with said upper re- .ector means in directing laterally from both 6 sides of the `sterilizer ultraviolet radiations emitted by said lamp.

,10. An ultraviolet sterilizer, comprising anelongated support having a pair of longitudinally spaced lamp holders depending therefrom7 a tube type ultraviolet lamp extending between and carried by said lamp holdersl beneath and spaced from said support, elongated upper reflector means, carried by said support in 'the space between it and said lampiand having upwardly and y laterally disposed downwardly facing reflector'r portions lyingpon opposite sides of the vertical plane of the longitudinal axis of said lamp, and

`suspended from-said support and cooperable with said upper reflector means indirecting laterally upwardly facing elongated lower reflector' means from bothsides of the sterilizer ultraviolet radia- -tions emitted by said lamps.

' 11. An- ,ultraviolet sterilizer,` comprising an elongated support having a pair of longitudinally spaced lamp holders depending therefrom, a tube type ultraviolet lamp extending between and carried by said lampl holders beneath and spaced ,f portions lying on opposite sides ofthe vertical plane of the longitudinal axis of said lamp, and

elongatedlower reflector means suspended from n saidr support and having upwardly and laterally disposed upwardly facing reflector portions lying `on-opposite sides of the aforesaid vertical plane for cooperation with said upper reflector means in directing laterally from bothv sides of the sterilizer `ultraviolet radiationsiemitted by said'` lamp. i

12.` An ultraviolet sterilizer, comprising an elongated housing open at its bottom, a cover t plate for the bottom opening of said housing,

longitudinally spaced lamp holders having por-l tions thereof lying `within said housing and secured; tosaid cover plate and having other portions projecting=through andbelow saidcover plate, a .tube .type ultraviolet lamp extending between and Carried by the downwardly projecting portions ofsaid lamp holders, a ballast for said `lamp llyingwithin said housing and secured to said cover plate, wiring electrically connecting said llamp holders and said ballast and lying within saidhousing, end plates secured to and depending from said housing' downwardly facing elongated reflector means carried byf said cover plate and located between such plate and said lamp, and upwardly facing reiiector means extending between and carried by said end plates for directing upwardly and laterally from both sides of the sterilizer ultraviolet radiations emitted by said lamp.

13. An ultraviolet sterilizer, comprising an elongated support having a pair of longitudinally spaced lamp holders depending therefrom, a tube type ultraviolet lamp extending between and carried by said lamp holders beneath said support, a ballast for said lamp carried by said support, elongated reector means suspended from said support for directing laterally from both sides of the sterilizer ultraviolet radiations emitted by said lamp, said reflector means having an opening beneath said lamp to permit some of the ultraviolet radiations emitted by said lamp to pass l ydownwardly therethrough.

14. An ultraviolet -sterilizer,` comprising an elongated support having a pair of longitudinaIly spaced lamp holders depending therefrom, a tube type ultraviolet lamp extending between and carl ried by said lamp holders beneath said support, and upwardly `facing elongated reflector portions suspended from said support vfor directing laterv ally from both sides of the sterilizer ultraviolet radiations emitted by 'said lamp, said reflector portions being separated by an opening located below said lamp and permitting some of the ultraviolet radiations emitted by said lamp to pass downwardly therethrough.

ROBERT A. HRABAK. 

